Drafting-machine



A. M. BUTTERFIELD.

DRAFTING MACHINE.

APPLICATION FILED MAY 19. I920.

Patented Nqv. 30, 1920.

2 SHEETS-:SHEEI mdl 3 5 5 E a. Q 2 m4. 3 3

A. M. BUTTERFIELD.

DRAFTING MACHINE- APPLICATION FILED MAY19,1920.

Patented Nov. 30, 1920.

2 SHEETS-SHEH 2.

ANDREW MAURICE BUTTERFIELD, 0]? BATH, MAINE.

DRAFTING-MACHINE.

Specification of Letters Patent.

Application filed May 19. 1920. Serial No. 382,553.

T 0 all whom it may concern:

Be it known that I, ANDREW M. BUTTER- FIELD, a citizen of the United States, and

resident of Bath, county of Sagadahoc, State of Maine, have invented certain new and useful Improvements in Drafting-Machines, of which the following is a specification.

One object of the invention is to provide a drafting implement which will facilitate the work of the draftsman in making plans or drawings involving, for instance, base lines running at an inclination to the sheet and generally referred to as angular drafting.

One form of drafting machine extensively used is provided with a protractor by which the draftsman may get ordinary angles such as 30,45, and 90 and also odd angles in respect to a horizontal or a vertical line, but in this form of machine in making a drawing whose base line or whose main part is not horizontal or vertical in relation to the drawing board edges, then the machine has to be set for this angular variation and locked and it is inconvenient to work from this new angular position, because it is necessary in doing so to make computations.

In carrying out my invention I combine with the head of the machine at which a protractor of substantially usual form and combined with the scales, is located, a base plate and what I term for convenience a base protractor so that the angularity of the base line may be determined and the usual protractor automatically set in zero position to correspond with this angular position of the base line from which position the last named protractor maybe set to get angular positions of varying degrees from this angular base line in the same manner as is customarily done from a horizontal or vertical base line.

In the accompanying drawings Figure 1 is a plan view of the implement with portions thereof broken away.

Fig. 2 is a central vertical sectional view through the head.

Fig. 3 is a side view of the anchor plate and adjacent parts.

Fig. 4 is a sectional view similar to Flg. 2, but showing only the base plate and the combined stop-pin plate and base protractor.

Fig. 5 is a plan view of the base plate.

Fig. 6 is a plan view of the stop-pin plate with the base protractor combined therewith.

In the drawings, 5 indicates the anchor plate which is screwed to the drawing board and to which is pivotally connected a yoke 4, by means of the pivotsj 1 and 3. At 2 is shown an adjusting screw carried by the yoke 4' and resting on the anchor plate by which the yoke may be adjusted in relation to the anchor. This yoke has the parallel bars 6 pivoted thereto at 6 and these bars are pivoted to a ring 7 to which also other bars 8 are pivoted, the latter being pivoted to a plate 9 which is secured by bolts 20 to a base plate 11.

The ordinary protractor is shown at 22, this being combined with the rulers or scales 19 in substantially the ordinary manner.

The base plate 11 has a center post or pivot pin 14 riveted thereto and the protractor 22 is turnable about this pin. I interpose between this protractor 22 and the base plate 11 what I call a base protractor 12, this being turnable about the center post 14 and having a slot 12 concentric with the center post 14. A clamp post 21 fixed in the base plate 11 extends up through the slot 12 in the base protractor and a clamping nut 21 on the upper screw, threaded end of this post clamps the base protractor to the base plate in the relative position shown in Fig. 1 or in any angular position within the limits allowed by the slot, it being observed that the base protractor is provided with a scale cooperating with an indicator 10 which is riveted in the base plate 11 as indicated in Fig. 2 and Fig. 4. The indicator for the protractor 22 is shown at 32, this being. riveted to the base protractor 12 as shown in Fig. 4.

The base protractor has a series of openings 12 adapted to receive the spring pressed pin 17 by which the protractor plate 22 can be set at different angles to the base protractor This pin is carried by the main protractor plate. It is pressed by a spring 23 secured at 22' to the protractor 22 and it operates through a bushing. or sleeve 16 clamped to the plate 22 by a nut 16'.

By means of the base protractor 12 com bined with the base plate 11, and adjustable in relation thereto by means of its scale and indicator the implement can be initially set i to a base line which is at any desired inclination to theedges of the paper ona horizontal or vertical line thereon. this\adjustment being efiected by moving the protractor 12 about the center post 14 and securing it in position by means of the clamp 21 and this Patented Nov. 30, 1920.

adjustment having been effected, the protractor 22 may be set in relation to this inclined base line in the same manner that protractor 22 heretofore has been set in relation to its usual center position or in other words in relation to a horizontal or vertical base line. 7

In making the above mentioned initial adjustment with the protractor 12, the protractor 22 goes with it and remains at its Zero position as indicated, by its scale, and its indicator 32, which in my improvement is mounted on the base or additional protractor 12 and the new angular position having been attained any desired angles of the rulers can be obtained from this new position without making calculations. hen the clamp 21 is released all the parts above the base plate 11 can be turned about the center post 1d as one body. When clamp 21 is set, all the parts above the protractor 12 can be turned about the center post 14: by lifting the spring pin 17 by the thumb lever 27.

Referring to the details shown, 13 is a nut and 13 a bushing which is held by the nut to the protractor 22 and scale arm 29, said bushing being turnable about the center post 14:. A washer 25 screwed to the post overlies the bushing, to hold it on the center post and a. spring 26 serves to hold the base plate 11, protractor 12 and protractor 22 and scale arm 29 in proper relation face to face.

15 is a fiat spring seated under the nut 13 and bearing on the thumb lever 27 to hold it under restraint.

18 is a clip which steadies the relative movement of protractor 12 and scale arm 29 preventing the spring 23 from separating them.

30 are chucking plates carried by scales 19.

24 is a hand knob by which protractors 12 or 22, or 22 alone may be turned.

28 is a clamping lever the boltof which extends through scale arm 33 and clips over protractor 12 and when tightened allows protractor 22 to be locked to protractor 12 'at any odd angle at which the stop pin 17 does not register with the holes in the protractor plate 12.

It will be seen from the above that I provide the means for securing an initial angular position of the instrument in a most convenient manner by arranging the additional or base-line protractor at the head of the instrument, associating it with the base plate and with the protractor 22, heretofore located elsewhere. I-Iereall adjustments are convenient to the draftsmans hand, and directly under his eye.

I claim i l. A drafting machine comprising an anchormember, a protractor, scale arms connected'therewith, a base plate, on which said protractor is mounted, connections between the base plate and the anchor by which the base plate may be set in different positions and a base protractor adjustably mounted on the base plate to determine the base line or angular position of the drawing, the protractor first mentioned being adjustable in relation to the said base protractor to set the scale arms at different angles relative to the base line, substantially as described.

2. A drafting machine comprising an anchor, a head, connections between the ancl'ior and head, said head comprising a base plate having a center post mounted thereon. a base protractor adjustable about the said post, an

indicator on the base plate for said base pro tractor, scale arms, a main protractor member carrying said scale arms, an indicator for the last mentioned protractor carried by the base protractor and means for securing the main protractor in adjusted position relatively to the base protractor, substantialh as described.

3. A drafting machine comprising an anchor, a head, connections between the anchor and head, said head comprising a base plate. having a center post mounted thereon, a base protractor adjustable about the said post, an indicator on the base plate for said base protractor, scale arms, a main protractor member carrying said scale arms, an indicator for the last mentioned protractor, carried by the base protractor and means for securing the main protractor in adjusted position relatively to the base protractor, said means comprising a locking pin carried by the main protractor and engaging openings in the base protractor, substantially as described.

4. In combination in a drafting machine. an anchor, a head having a base plate with connections between said base plate and an chor, a post carried by the base plate, a protractor member adjustable about the post and having a slot concentric with the post and a clamp passing through the slot for fixing the protractor to the base plate in dif ferent positions, an indicator for the said protractor, a main protractor carrying scale arms adjustable about the axis of the center post, an indicator therefor carried by the base protractor and means for fixing the scale arm protractor to the base protractor. substantially as described.

5. In combination, a base plate having a center post, a base protractor adjustable about said post, a sleeve surrounding the post above the said base protractor, a scale arm and a main protractor surrounding the sleeve, a nut for holding the said parts, a member connected to the post and holding the sleeve thereon, and a spring for holding the parts in contact, substantially as described.

In testimony whereof, I affix my signature.

ANDREW MAURICE BUTTERFIELD, 

